passwd(5yp)passwd(5yp)Namepasswd - password file description with the Yellow Pages service imple‐
mented
Description
The file stores initial login information, including passwords for each
user in the system. Regardless of whether or not the system has the
Yellow Pages service implemented, the file contains the following
information:
Name (login name, contains no uppercase)
Encrypted password
Numerical user ID
Numerical group ID
User's real name, office, extension, home phone.
Initial working directory
Program to use as Shell
The name can contain an ampersand (&), meaning insert the login name.
This information is set by the command and used by the command.
This is an ASCII file. Each field within each user's entry is sepa‐
rated from the next by a colon. Each user is separated from the next
by a new line. If the password field is null, no password is demanded;
if the shell field is null, the system defaults to the shell.
This file resides in the directory. Because of the encrypted pass‐
words, it can and does have general read permission and can be used,
for example, to map numerical user IDs to names.
Appropriate precautions must be taken to lock the file against simulta‐
neous changes if it is to be edited with a text editor. The command
does the necessary locking.
In a Yellow Pages environment, the file can also have a line beginning
with a plus (+), which means to incorporate entries from the Yellow
Pages data base. There are three styles of + entries: by itself, +
means to insert the entire contents of the Yellow Pages password file
at that point; +name means to insert the entry (if any) for name from
the Yellow Pages at that point; +@name means to insert the entries for
all members of the network group name at that point. If a + entry has
a nonnull password, directory, gecos, or shell field, it will override
what is contained in the Yellow Pages. The numerical user ID and group
ID fields cannot be overridden.
Examples
Here is a sample file:
root:q.mJzTnu8icF.:0:10:Privileged Account:/:/bin/csh
jcj:6k/7KCFRPNVXg:508:10:JC Javert:/usr2/jcj:/bin/csh
+john:
+@documentation:no-login:
+:::Guest
In this example, there are specific entries for users root and jcj, in
case the Yellow Pages are temporarily out of service. Alternatively, a
user may need specific login information on a given system that differs
from the information contained in the Yellow Pages map for that user.
The user, john, will have his password entry in the Yellow Pages incor‐
porated without change. Anyone in the netgroup documentation will have
their password field disabled, and anyone else will be able to log in
with their usual password, shell, and home directory, but with a gecos
field of Guest.
FilesSee Alsochfn(1), finger(1), login(1), passwd(1), crypt(3), getpwent(3),
group(5), adduser(8), vipw(8)passwd(5yp)
